The major goal of this work is to test at the molecular level the proposed control model for transfer of the antibiotic resistance plasmid R100. These studies will test directly the protein-protein and protein-DNA interactions of the presumed control genes finO, finP, traJ. The approach involves restriction mapping, DNA sequencing, filter binding assays and hybridization studies. The DNA sequence data will be used to identify the pilin precursor protein by comparing it to the partial amino acid sequence of R100 pilin.